Category Archives: Allgemein

My PC is a Toaster – Literally!

I have been told that a crappy PC is called a toaster. Now I actually had a pretty crappy PC that badly needed a case – in my kitchen. And I had an old toaster large enough to house my mini-ITX components. What els could I do but this:

I wanted it to be as toasty as possible

Like any other toaster you start it by pushing down the lever, and it will gently start to glow. The intensity of the glow can be regulated with the knob at the front.

I don’t know when I have last used a DVD, but this build just had to have two slot loading optical drives at the top. And when you press the butoon that normallly ejects the toast slices, my version will eject both disks instead.

And when you power it down, the glow fades away and the lever pops back up.

I had this old toaster lying around

Let’s see how we get in there

Coronavirus: lightweight 3D printed spit shield visor

During the pandemic, we are all requested to stay apart reduce the risk of infection, but health workers around the globe risk their own health working very close to patients. The most common way the Coronavirus spreads seems to be through droplet infection: Small droplets of spit are launched into the air when an infected person coughs, sneezes, or even speaks and enter the eyes nose or mouth.

One way to reduce the risk of droplet infection is wearing a face shield. So many owners of 3d printers fire up their machines to help provide this kind of personal protective equipment. However, many of the models that can be found on the internet are held to the head with a rubber band and can be quite uncomfortable, especially if you need to work with them all day.

That is why I came up with my own design, that is very lightweight and worn like glasses.

It can be printed in almost any material, I have used PLA. It requires no support and uses only 13g of material, so material costs are pretty low and the printing is very fast. The nose piece is printed separately and has to be pushed into the main part. That way, you can print it pretty fast, and the print can also be sent in an envelope

The transparent plastic is overhead film with holes for a 4 ring binder. I bought mine on ebay and punched the holes myself. The easiest would be a hole punch that punches all four holes at the same time, but any hole punch will do. The film simply clips onto the print.

Here are the STL-files.

PC-In-A-Bag – DIY computing to go –Part 1

Are you sometimes frustrated with the lack of computing power in mobile devices? I Built a device that looks somewhat like a large tablet, but has the computing power of a fully crown PC – no wonder, because it is: The pc itself is hiding under the table. It is permanently built into a leather messenger bag that also has room for the tablet, which is in fact a portable monitor.

A Mini-ITX motherboard, a graphics card and a power supply unit are permanently installed in the bag. A portable touch screen monitor with Full HD resolution is attached via a cable. It also fits in the bag, just like the small Bluetooth keyboard with trackpad and a mouse.

Unlike a laptop, I don’t have a battery in my bag – not yet – but the computer also runs on the cigarette lighter in the car. And at home I can also connect a large monitor and even use both monitors together.

By the way, the pocket computer is very quiet, because it needs only two fans. The processor fan and the graphics card suck in the air directly from outside, which is then released upwards and through the power supply unit.

I’ve been looking for a suitable bag for a long time. I finally bought this one on ebay. These parts are to be installed: A Mini-ITX motherboard with Intel Core I5 6500 processor and a very quiet and flat fan from Noctua as well as 16 GB Ram. An MSI Radeon RX 560 Aero graphics card with 4GB video RAM. Because the two parts are to be mounted next to each other, I need a PCIE riser cable of 20cm length.

Also a 12V power supply, which here has 350 watts, and an M2-ATX power supply, which generates all the voltages that the components need from an input voltage of 6 to 24V. I exchanged it afterwards, by the way, but more about that later.

I had a piece of plywood cut to the inside dimensions of the bag at the DIY store.
Now the components have to be puzzled. And don’t forget that the cables also need space. That’s how it fits.We also need a harddisk. I chose an SSD. In principle, this would still fit next to the power supply unit. Only the cables will stick out too far.

But the plastic housing is only there to give the SSD the dimensions of a 2.5″ hard disk. So I muster the courage to crack the case open. That is actually quite simple, and the actual SSD is not even half the size. Now it has plenty of room. To mount and protect the it, I designed and printed a case that the SSD snaps into and which I can then screw onto the base plate.

I also printed a bunch of brackets.

First I provisionally put the screws through the motherboard to determine the position of the brackets. I then marked them with a pencil. I mixed two-component glue and glued on the parts. For the graphics card I have printed parts that the circuit board snaps onto. These is also glued on. Because the parts kept moving around, I additionally fixed them with hot glue.

Then I marked and drilled the holes. On the back I enlarge the holes with a larger drill bit to countersink the screw heads, because I want to keep a smooth surface. Then the various parts are screwed onto the base plate. The screws are very deep in the whole parts. So I put three nuts in the nut and put the plate on its side to get the nuts on the screws.

I plug in the various cables. I would have been better installed the IO-aperture right away, now that the motherboard is screwed in place, it is a bit complicated.

That’s it for now, the build will be continued next week.

Automatic Door for the Cat – with HC-SR501 motion detector, without arduino

Even complex project can be done without an arduino. I built an automated door with two HC-SR501 infrared motion detectors.

I use a linear actuator to open the door. This one is from Aliexpress, like everything else, and has limit switches. That means when it reaches either end, it just stops.
In addition, two infrared motion detectors are used, which do not even cost one euro in China. The links are in the description.
We also need a relay with a double changeover switch, an NPN transistor, a diode, and a resistor.
Because the output signal of the motion detectors is not powerful enough to switch the relay, we use the transistor as an amplifier.
The diode is required to protect the rest of the electronics from voltage spikes produced by the relay.
On the switching side, the relay is also connected with plus and minus. In idle mode, the voltage is connected to the last two pins.
If one of the motion detectors detects a movement and outputs a voltage, the relay switches on and the voltage is applied to the other output pins. If we connect them crossed with the last pins, the polarity is reversed and the linear motor runs in the other direction until it stops at the end stop. Continue reading Automatic Door for the Cat – with HC-SR501 motion detector, without arduino

MM: 3D-Printed Universal Paint Adaptor for Nail Polish Shaker

This is the start of a new series: I am going to publish very short videos on Mondays. Not every Monday, but every now and then. In this episode:

3D printed Adaptor for a nail polish shaker to shake modelling acrylic paint, airbrush colors and whatever might need shaking.

The two parts of the adapter are being connected with the springs that are included with the nail polish shaker. The adapter is then being inserted into the ring on the device, because of it’s “wings” it won’t fall out. Happy shhaking!

The STL file is here for downloading.

This is the nail polish shaker on,

DIY Salamander / Beefer / Overhead broiler for 35,-€

For the hefty price tag of at least 800 Euros you can buy exotic gas grills like the O F B – Over Fired Boiler – from Otte Wilde or the Beefer. Both of them produce an immense heat that comes only from the top. In the professional kitchen, this is known as a salamander or an overhead broiler. Now I’m sure that these are great products, but they are mostly for steaks, and you need to cook quite a lot of them to justify the expense. But  if you look closely at the beefer, you find a heating element that looks very similar to the one in this gas heater that you can buy for less than 35,- Euros. Maybe we can grill with that just as good? Let’s find out!

Such a gas heater is available for less than 35 euros:

And quite conveniently, there’s even a grill grid included: The protective grate in front of it. We need to get our food as close to the heating element as possible. The edge of the heater is in the way, so it has to go. By the way, if you want to do this, please do it at your own risk, I don’t take over any liability. But we only fiddling with combustible gas under high pressure, what could possibly go wrong?

The grill grid is removed. Now I’m building a foundation out of some stones that were lying around here. Fits. Let’s give it a try. I got myself some beef steaks.

After about a minute, the steak is turned around.

I’ve been experimenting with the distance. Because the grill grate is not adjustable, I simply put some spacers under the heater.

Down below, the first steak is heated to the right core temperature.

It takes some practise, and a proper casing might be helpful, but all in all I am pretty happy with the result.

Better Than a Ring Light – DIY Logo Light

A ring light is so 2017! Everyone has it, and it makes you look like a husky. How about a logo light?

First I need my logo on a piece of plywood. I simply printed it out on 6 sheets of paper. But marking would have worked in the same way. How big? This depends on the desired distance, but it can’t hurt to make it really big. My logo is approx. 60x 80 cm in size, and in the opening credits I am only one arm’s length away from it. I stick my sheets together and add the missing bits of the contour on the margins. Then I cut out the logo. I stick it to the plywood board with a glue stick.

Now an LED strip is used. When you buy an led strip for photography or video purposes, look for a high CRI value (color rendering index). It should be 80 or above.
If you are going to use it alongside other lighting equipment, I would suggest that you match the color temperature. I use 4000k for all my lights.

Compare these LED-Strips:*****

There are special bendable LED strips, but normal strips can also be guided around curves if you fold them a little.

The LED strips can be cut at the marks – with particularly beautiful scissors. I try to cover the logo as evenly as possible with the LED strips. The direction doesn’t matter.

There are soldering points on the LED strips at regular intervals. All strips are connected in parallel. It doesn’t matter where, as long as it’s plus to plus and minus to minus. To connect several pieces with one cable, I like to cut only the insulation. Then pull the insulation apart a little so that the bare copper is exposed and I can solder it on. Maybe I should have been more careful about the polarity though.

After everything is connected, I secure the LED strips with hot glue, I don’t really trust the adhesive layer of the strip.

Now I need cardboard strips with a width of approx. 3.5mm. It doesn’t really matter, but it helps when they are straight and all the same width. I just took a strip of wood as a measure.

Now may be a good time to saw out the hole through which the camera is supposed to look later.

Now I glue the cardboard strips along the whole contour of the logo.

So that the individual LEDs are no longer visible, we need a diffuser. I use tracing paper. This is glued to the edge of the cardboard contours with hot glue.

Now I build a simple bracket.

The connecting plate is screwed between camera and tripod quick mount plate.

And the plywood with the logo is glued on with plenty of hot glue. I can’t screw it on, I should have done that before gluing on the tracing paper.

The result works just as a ring light, only that the camera picks up the reflection of the logo instead of a boring old ring. Try it out!

DIY Camera Trap – How to control the shutter of a Panasonic Lumix with Arduino and HC-SR501 Motion Detector

Wouldn’t it be great to have a camera that starts recording when something moves? If you look for “wildlife camera” or “camera trap” you can buy cameras that do just that. But first, they are quite expensive, and second, the image quality leaves a lot to be desired. But most cameras have a connection for a remote release. Can’t we combine that with a motion sensor?

I ordered some of these HC-SR501* infrared or PIR motion detectors from Aliexpress, a link is in the description. The sensitivity and the duration of the switching time can be set on the two potentiometers on the side, for example for a light that is to remain switched on for a certain time. That doesn’t help us, because we need a start impulse at the beginning and a stop impulse at the end of the recording. We need an Arduino for that. Now the remote shutter release on my Panasonic Lumix works measuring the resistance of whatever is connected to the socket.

Schematic of Panasonic Lumix Remote Shutter Release Pinout, Will suit G3, G4, Gh4, Gh3, Gh5, G7, G70
Schematic of Panasonic Lumix Remote Shutter Release Pinout, Will suit G3, G4, Gh4, Gh3, Gh5, G7, G70

I don’t use the Focus button here. So I use an optocoupler instead of the shutter push button on the remote. This is a double one, a single one would have done it, but I still had this one. Continue reading DIY Camera Trap – How to control the shutter of a Panasonic Lumix with Arduino and HC-SR501 Motion Detector